VTF-15: your settings?

[jlm86]

I am interested to see what others' actual settings are on their subs....

Can you give me your EQ and ouput settings you have currently found to be a nice setting you have found...

thank you

[GARoss]

I have 2) VTF-15Hs.

• Both ports open
• EQ2 & volume @ 20-25%.
• Setup using RS meter using the included CD to Dr Hsu's recommendations for balanced audio.
• My theater is 14x26' with 8' ceiling & includes bass traps & audio damping material.

HTH

[OZZ]

I have one VTF-15H on my longest corner with EQ=2 Q=.3 both ports open
used an RS meter with the supplied disc and volume is 8;45 on the sub to obtain 0 setting out on my AVR.

[Peaces]

I have 2 VTF-15Hs in a 18' x 30" room. I have had this setup for about 3 months now waiting to do some tweaking after all the furniture/wall coverings, etc... was settled.

I too am very interested in other's settings because I have not ventured beyond the recommendations by Dr HSU as to calibrating using Audyssey (Onkyo TX-ND5009)
After calibration...
2 ports open
EQ 2
.o3

Although I have been an audiophile for over 4 decades I am still a novice at dealing with the sub-woofer. Mainly because these two are really my first pair of any substaintial quality.

My questions begin with:
1) What am I listening for if I start changing... the EQ from .03 to .05 or .07?
2) Is there a good reference CD or DVD for tweaking the sub settings?
3) Should I even need to consider changing the crossover? My mains are 30+ year old JBL L-250s with all new coning that still rocks. They do house a 12" woofer that is supposed to be flat to 30hz.
4) If I do play with the crossover... where should I start and again, what am I listening for?

I absolutely love this pair of subs but if I can get more out of them... I wanna give it a try.

One additional question for those who use Audyssey... after calibration if I want any kind of lower end I always have to bump the volume on the back of each sub to at least to the first mark+. Is this normal when using Audyssey? (when starting the calibration it requires me to set the sub DBs to 75)

Thoughts?

Thanks... Warren

[OZZ]

Nice setup but I hope those subs are not set in the middle of the room length because thats where the ugly null resides I had the same problem in my room with seating so I pulled the easy chairs forward a couple of feet from center making a big difference.

[Peaces]

They are and I might entertain making some minor changes to their location.

However, what you can't see is the ceiling is 9' and to the left side there is a 10' x 8' opening to another room (12'x18' which is open to another larger room) and under me is an opening (4'x6') to our dining room and also a door sized opening to the kitchen below on the right. So there is much more opened to the direction of the subs than just the 18'x30' room.

I also realized that some of my thoughts and questions were very immature after doing more reading as to the Audyssey settings and the crossover between it's calibration and what I have set on the subs. I'll be doing some tweaking and see where it takes me. I definitely realize that I need to change the speaker size of my mains in Audyssey and let the subs do more of the work.

Thanks for the input.

[SME]

Your setup looks great! My own setup is vaguely similar to yours with a VTF3-MK4 and a VTF-15H on either side of the sofa. My room is smaller, and I actually run with 1 port plugged, EQ1, and Q=0.7 all the time. Not only that, but I calibrated with 1 port plugged, EQ1, and Q=0.3 before setting Q=0.7 because Audyssey was my deep bass was too low after calibration. I think my calibration mic is picking up vibrations through my hardwood floor.

Now to answer your questions with a small novel:

First off, definitely set all your speakers to "small" and crossovers to at least 80 Hz. I recommend listening and testing with Audyssey Dynamic EQ engaged. Otherwise, you should do all your test listening at the same volume level, relative to the level the tracks were mixed at; typically that's 0 dB for movies and -10 dB for most music. If using Dynamic EQ, set the "reference offset" (it may have another name) to 0 dB for movies or 10 dB for music.

Now let me note something important about how sound is perceived. With decreasing frequency:

• perceived loudness decreases
• dynamic range of human hearing decreases
• the lowest pressure level that a sound can be perceived at increases

At 1 kHz, +10 dB "sounds like" a doubling of sound level, but in the bass region, one perceives a doubling after only 3 to 5 dB. This also means that as you decrease the volume (without Audyssey Dynamic EQ or other compensation enabled), the deep bass drops out faster than the rest of the sound.

Masking is the phenomena in which a quieter sound cannot be heard over a louder sound playing at a similar but not identical pitch. Masking becomes more severe in the bass region. In other words, sounds that are more similar in level or are farther from each other in pitch are more likely to mask one another. This means that if deep bass and mid bass response are off by more than a couple dB, a lot of detail is never heard.

Having discussed these points, here are the qualities I see as important to a good bass experience:

1. Sufficient dynamic headroom for the chosen playback volume

The importance of headroom should be obvious. Without it, dynamics will be limited and loud passages will be distorted. You also won't achieve (2) when you are out of headroom. If you think you are hitting this limit, try playing the track at a lower volume (works best with Dynamic EQ and correct "reference offset"). If it sounds cleaner and more detailed, then headroom may be an issue.

2. Flat perceived response

This is critically important, as discussed above, because of masking. In theory, Audyssey calibrates your system for a flat response, but in practice, it doesn't always get it right. A few dB can be the difference between hearing and not hearing, so you need all the help you can get. Thankfully, the Q control let's you adjust the balance between low and mid bass after running calibration. I suggest tuning this by ear rather than with an SPL meter. Listen to a variety of movie scenes with interesting bass and experiment with different Q values. You want the setting that yields the richest and most detailed sound.

3. Temporal accuracy

This concerns how "tight" the bass sounds. This is more important for music than for movies. Basslines should be clean and distinct, even when mixed at a low level. Kick drums should be full and well-integrated with no extra "whoomh" sound appearing after the initial punch. Because temporal distortion tends to get worse with lower frequencies, one may opt to decrease Q to tune out deep bass that distracts rather than contributes to the sound.

Temporal accuracy depends on sub placement and how many ports are plugged. Placements away from room modes tend to provide more accuracy at the expense of headroom; hence, placing subs in nulls may not be that bad if you are sitting close enough. The port(s) contribute a lagging response, which affect temporal accuracy of lower frequencies. The trade-off is arguably worthwhile for the deep bass output these subs achieve. Running the sub with one port plugged can improve temporal accuracy by decreasing the frequency that the port(s) begin to contribute to the sound. This works with either EQ 1 or EQ 2. You can tighten up the sound further with both ports plugged, but the substantial loss of headroom usually doesn't make it worth it.

So in summary:

• Use Dynamic EQ if possible and set the "reference offset" for the type of mix
• Experiment with the Q control; adjust to balance the deep and mid bass response or to tune out unwanted "sloppy sounding" deep bass in music
• Plug one port for a tighter sound at the expense of slightly diminished headroom; you can run either EQ 1 or 2 with one port plugged

I'd wager you'd get an improvement with a higher Q, given that your room is large, and your subs are close, symmetric, and away from the walls. You may find you were missing out on a lot of subtle, deep bass detail!

[Peaces]

WOW... thanks for taking the time to write all of this out. I will seriously take your input and go play.